Add missing includes and forward declarations

I looped over the toplevel header files, creating a temporary two-line C
program for each consisting of
  #include "git-compat-util.h"
  #include $HEADER
This patch is the result of manually fixing errors in compiling those
tiny programs.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/alloc.h b/alloc.h
index 3e4e828..7a41bb9 100644
--- a/alloc.h
+++ b/alloc.h
@@ -1,9 +1,11 @@
 #ifndef ALLOC_H
 #define ALLOC_H
 
+struct alloc_state;
 struct tree;
 struct commit;
 struct tag;
+struct repository;
 
 void *alloc_blob_node(struct repository *r);
 void *alloc_tree_node(struct repository *r);